Sex Differences in Severity of Stroke in the INSTRUCT Study: a Meta-Analysis of Individual Participant Data

Background

Women have worse outcomes after stroke than men, and this may be partly explained by stroke severity. We examined factors contributing to sex differences in severity of acute stroke assessed by the National Institutes of Health Stroke Scale.

Methods and Results

We pooled individual participant data with National Institutes of Health Stroke Scale assessment (N=6343) from 8 population‐based stroke incidence studies (1996–2014), forming part of INSTRUCT (International Stroke Outcomes Study). Information on sociodemographics, stroke‐related clinical factors, comorbidities, and pre‐stroke function were obtained. Within each study, relative risk regression using log‐binominal modeling was used to estimate the female:male relative risk (RR) of more severe stroke (National Institutes of Health Stroke Scale>7) stratified by stroke type (ischemic stroke and intracerebral hemorrhage). Study‐specific unadjusted and adjusted RRs, controlling for confounding variables, were pooled using random‐effects meta‐analysis. National Institutes of Health Stroke Scale data were recorded in 5326 (96%) of 5570 cases with ischemic stroke and 773 (90%) of 855 participants with intracerebral hemorrhage. The pooled unadjusted female:male RR for severe ischemic stroke was 1.35 (95% CI 1.24–1.46). The sex difference in severity was attenuated after adjustment for age, pre‐stroke dependency, and atrial fibrillation but remained statistically significant (pooled RR_adjusted 1.20, 95% CI 1.10–1.30). There was no sex difference in severity for intracerebral hemorrhage (RR_crude 1.08, 95% CI 0.97–1.21; RR_adjusted 1.08, 95% CI 0.96–1.20).

Conclusions

Although women presented with more severe ischemic stroke than men, much although not all of the difference was explained by pre‐stroke factors. Sex differences could potentially be ameliorated by strategies to improve pre‐stroke health in the elderly, the majority of whom are women. Further research on the potential biological origin of sex differences in stroke severity may also be warranted.

Effectiveness of a scalable group-based education and monitoring program, delivered by health workers, to improve control of hypertension in rural India: A cluster randomised controlled trial

BACKGROUND

New methods are required to manage hypertension in resource-poor settings. We hypothesised that a community health worker (CHW)-led group-based education and monitoring intervention would improve control of blood pressure (BP).

METHODS AND FINDINGS

We conducted a baseline community-based survey followed by a cluster randomised controlled trial of people with hypertension in 3 rural regions of South India, each at differing stages of epidemiological transition. Participants with hypertension, defined as BP ≥ 140/90 mm Hg or taking antihypertensive medication, were advised to visit a doctor. In each region, villages were randomly assigned to intervention or usual care (UC) in a 1:2 ratio. In intervention clusters, trained CHWs delivered a group-based intervention to people with hypertension. The program, conducted fortnightly for 3 months, included monitoring of BP, education about hypertension, and support for healthy lifestyle change. Outcomes were assessed approximately 2 months after completion of the intervention. The primary outcome was control of BP (BP < 140/90 mm Hg), analysed using mixed effects regression, clustered by village within region and adjusted for baseline control of hypertension (using intention-to-treat principles). Of 2,382 potentially eligible people, 637 from 5 intervention clusters and 1,097 from 10 UC clusters were recruited between November 2015 and April 2016, with follow-up occurring in 459 in the intervention group and 1,012 in UC. Mean age was 56.9 years (SD 13.7). Baseline BP was similar between groups. Control of BP improved from baseline to follow-up more in the intervention group (from 227 [49.5%] to 320 [69.7%] individuals) than in the UC group (from 528 [52.2%] to 624 [61.7%] individuals) (odds ratio [OR] 1.6, 95% CI 1.2-2.1; P = 0.001). In secondary outcome analyses, there was a greater decline in systolic BP in the intervention than UC group (-5.0 mm Hg, 95% CI -7.1 to -3.0; P < 0.001) and a greater decline in diastolic BP (-2.1 mm Hg, 95% CI -3.6 to -0.6; P < 0.006), but no detectable difference in the use of BP-lowering medications between groups (OR 1.2, 95% CI 0.8-1.9; P = 0.34). Similar results were found when using imputation analyses that included those lost to follow-up. Limitations include a relatively short follow-up period and use of outcome assessors who were not blinded to the group allocation.

CONCLUSIONS

While the durability of the effect is uncertain, this trial provides evidence that a low-cost program using CHWs to deliver an education and monitoring intervention is effective in controlling BP and is potentially scalable in resource-poor settings globally.

TRIAL REGISTRATION

The trial was registered with the Clinical Trials Registry-India (CTRI/2016/02/006678).

Disparities in Antihypertensive Prescribing After Stroke

Background and Purpose—

Despite evidence to support the prescription of antihypertensive medications before hospital discharge to promote medication adherence and prevent recurrent events, many patients with stroke miss out on these medications at discharge. We aimed to examine patient, clinical, and system-level differences in the prescription of antihypertensive medications at hospital discharge after stroke.

Methods—

Adults with acute ischemic stroke or intracerebral hemorrhage alive at discharge were included (years 2009–2013) from 39 hospitals participating in the Australian Stroke Clinical Registry. Patient comorbidities were identified using the International Statistical Classification of Diseases and Related Health Problems (Tenth Edition, Australian Modification ) codes from the hospital admissions and emergency presentation data. The outcome variable and other system factors were derived from the Australian Stroke Clinical Registry dataset. Multivariable, multilevel logistic regression was used to examine factors associated with the prescription of antihypertensive medications at hospital discharge.

Results—

Of the 10 315 patients included, 79.0% (intracerebral hemorrhage, 74.1%; acute ischemic stroke, 79.8%) were prescribed antihypertensive medications at discharge. Prescription varied between hospital sites, with 6 sites >2 SDs below the national average for provision of antihypertensives at discharge. Prescription was also independently associated with patient and clinical factors including history of hypertension, diabetes mellitus, management in an acute stroke unit, and discharge to rehabilitation. In patients with acute ischemic stroke, females (odds ratio, 0.85; 95% CI, 0.76–0.94), those who had greater stroke severity (odds ratio, 0.81; 95% CI 0.72–0.92), or dementia (odds ratio, 0.65; 95% CI, 0.52–0.81) were less likely to be prescribed.

Conclusions—

Prescription of antihypertensive medications poststroke varies between hospitals and according to patient factors including age, sex, stroke severity, and comorbidity profile. Implementation of targeted quality improvement initiatives at local hospitals may help to reduce the variation in prescription observed.

Measuring stroke and transient ischemic attack burden in New Zealand: Protocol for the fifth Auckland Regional Community Stroke Study (ARCOS V)

Aim: The goal of this paper is to provide a protocol for conducting a fifth population-based Auckland Regional Community Stroke study (ARCOS V) in New Zealand. Methods and Discussion: In this study, for the first time globally, (1) stroke and TIA burden will be determined using the currently used clinical and tissue-based definition of stroke, in addition to the WHO clinical classifications of stroke used in all previous ARCOS studies, as well as more advanced criteria recently suggested for an "ideal" population-based stroke incidence and outcomes study; and (2) age, sex, and ethnic-specific trends in stroke incidence and outcomes will be determined over the last four decades, including changes in the incidence of acute cerebrovascular events over the last decade. Furthermore, information at four time points over a 40-year period will allow the assessment of effects of recent changes such as implementation of the FAST campaign, ambulance pre-notification, and endovascular treatment. This will enable more accurate projections for health service planning and delivery. Conclusion: The methods of this study will provide a foundation for future similar population-based studies in other countries and populations.

Early Mobilization After Stroke Is Not Associated With Cognitive Outcome

Background and Purpose- We aimed to determine whether early mobilization after stroke affects subsequent cognitive function. Methods- AVERT (A Very Early Rehabilitation Trial) was an international, 56-site, phase 3 randomized controlled trial, conducted from 2006 to 2015. Participants were included if they were aged 18+, presented within 24 hours of stroke, and satisfied physiological limits for blood pressure, heart rate, and temperature. Participants were randomized to receive either usual stroke unit care or very early and more frequent mobilization in addition to usual stroke unit care. The Montreal Cognitive Assessment, scored 0 to 30, was introduced as a 3-month outcome during 2008. Results- Of the 2104 patients included in AVERT, 317 were assessed before the Montreal Cognitive Assessment's introduction. Of the remaining 1787, 1189 (66.5%) had complete Montreal Cognitive Assessment data, 456 (25.5%) had partially or completely missing data, 136 (7.6%) had died, and 6 (0.3%) were lost to follow-up. In surviving participants with complete data, adjusting for age and stroke severity, total Montreal Cognitive Assessment score was no different in the intervention (n=595; median, 23; interquartile range, 19-26; mean, 21.9; SD, 5.9) and usual care (n=594; median, 23; interquartile range, 19-26; mean, 21.8; SD, 5.9) groups ( P=0.68). Conclusions- Exposure to earlier and more frequent mobilization in the acute stage of stroke does not influence cognitive outcome at 3 months. This stands in contrast to the primary outcome from AVERT (modified Rankin Scale), where the intervention group had less favorable outcomes than controls. Clinical Trial Registration- URL: https://www.anzctr.org.au . Unique identifier: ACTRN12606000185561.

Factors that confound the prediction of renal medullary oxygenation and risk of acute kidney injury from measurement of bladder urine oxygen tension

AIM

Urinary oxygen tension (uPO₂ ) may provide an estimate of renal medullary PO₂ (mPO₂ ) and thus risk of acute kidney injury (AKI). We assessed the potential for variations in urine flow and arterial PO₂ (aPO₂ ) to confound these estimates.

METHODS

In 28 sheep urine flow, uPO₂ , aPO₂ and mPO₂ were measured during development of septic AKI. In 65 human patients undergoing cardiac surgery requiring cardiopulmonary bypass (CPB) uPO₂ and aPO₂ were measured continuously during CPB, and in a subset of 20 patients, urine flow was estimated every 5 minutes.

RESULTS

In conscious sheep breathing room air, uPO₂ was more closely correlated with mPO₂ than with aPO₂ or urine flow. The difference between mPO₂ and uPO₂ varied little with urine flow or aPO₂ . In patients, urine flow increased abruptly from 3.42 ± 0.29 mL min^-1 to 6.94 ± 0.26 mL min^-1 upon commencement of CPB, usually coincident with reduced uPO₂ . During hyperoxic CPB high values of uPO₂ were often observed at low urine flow. Low urinary PO₂ during CPB (<10 mm Hg at any time during CPB) was associated with greater (4.5-fold) risk of AKI. However, low urine flow during CPB was not significantly associated with risk of AKI.

CONCLUSIONS

uPO₂ provides a robust estimate of mPO₂ , but this relationship is confounded by the simultaneous presence of systemic hyperoxia and low urine flow. Urine flow increases and uPO₂ decreases during CPB. Thus, CPB is probably the best time to use uPO₂ to detect renal medullary hypoxia and risk of post-operative AKI.

Sex differences in risk factors for aneurysmal subarachnoid haemorrhage: Systematic review and meta-analysis

BACKGROUND

Aneurysmal subarachnoid haemorrhage (aSAH) disproportionally affects women. We conducted a systematic review and meta-analysis to explore sex differences in aSAH risk factors.

METHODS

Case-control/cohort studies were searched to November 2017 with sex-specific risk factors for aSAH. Meta-analysis was performed when a risk factor was reported in ≥2 studies.

RESULTS

Of 31 studies, 22 were eligible for meta-analysis. Female sex was associated with greater odds of aSAH (HR_adjusted 1.90 [1.47-2.46]. There was no detectable difference between the sexes for hypertension (OR_adjusted: men 3.13 [2.26-4.34]; women 3.65 [2.87-4.63], p = .18), smoking (OR_adjusted: men 2.96 [1.68-5.21]; women 3.11 [1.21-7.97], p = .95), aSAH family history, systolic blood pressure, age and some genetic variations. Alcohol (OR_adjusted: men 1.50 [1.04-2.17]; women 0.83 [0.48-1.45], p = .003), high alanine aminotransferase levels, and some gene variants increased the risk of aSAH in men. Reproductive factors, divorce and some genetic variations increased the risk in women. High aspartate aminotransferase levels in men and, diabetes (OR_adjusted: men 0.57 [0.32-1.01]; women 0.24 [0.13-0.43], p = .01) and parity in women reduced aSAH risk.

CONCLUSION

We recommend sex-specific re-analysis of existing studies of aSAH risk factors. Known aSAH risk factors (hypertension, smoking and alcohol consumption) should be targeted to prevent aSAH in men and women. Registration PROSPERO (ID: CRD42018091521).

Sex Differences in Long-Term Quality of Life Among Survivors After Stroke in the INSTRUCT

Background and Purpose- Women are reported to have poorer health-related quality of life (HRQoL) after stroke than men, but the underlying reasons are uncertain. We investigated factors contributing to the sex differences. Methods- Individual participant data on 4288 first-ever strokes (1996-2013) were obtained from 4 high-quality population-based incidence studies from Australasia and Europe. HRQoL utility scores among survivors after stroke (range from negative scores=worse than death to 1=perfect health) were calculated from 3 scales including European Quality of Life-5 Dimensions, Short-Form 6-Dimension, and Assessment of Quality of Life at 1 year (3 studies; n=1210) and 5 years (3 studies; n=1057). Quantile regression was used to estimate the median differences in HRQoL for women compared to men with adjustment for covariates. Study factors included sociodemographics, prestroke dependency, stroke-related factors (eg, stroke severity), comorbidities, and poststroke depression. Study-specific median differences were combined into pooled estimates using random-effect meta-analysis. Results- Women had lower pooled HRQoL than men (median difference_unadjusted 1 year, -0.147; 95% CI, -0.258 to -0.036; 5 years, -0.090; 95% CI, -0.119 to -0.062). After adjustment for age, stroke severity, prestroke dependency, and depression, these pooled median differences were attenuated, more greatly at 1 year (-0.067; 95% CI, -0.111 to -0.022) than at 5 years (-0.085; 95% CI, -0.135 to -0.034). Conclusions- Women consistently exhibited poorer HRQoL after stroke than men. This was partly attributable to women's advanced age, more severe strokes, prestroke dependency, and poststroke depression, suggesting targets to reduce the differences. There was some evidence of residual differences in HRQoL between sexes but they were small and unlikely to be clinically significant.

Protocol for evaluation of enhanced models of primary care in the management of stroke and other chronic disease (PRECISE): A data linkage healthcare evaluation study

INTRODUCTION

The growing burden of chronic diseases means some governments have been providing financial incentives for multidisciplinary care and self-management support delivered within primary care. Currently, population-based evaluations of the effectiveness of these policies are lacking.

AIM

To outline the methodological approach for our study that is designed to evaluate the effectiveness (including cost) of primary care policies for chronic diseases in Australia using stroke as a case study.

METHODS

Person-level linkages will be undertaken between registrants from the Australian Stroke Clinical Registry (AuSCR) and (i) Government-held Medicare Australia claims data, to identify receipt or not of chronic disease management and care coordination primary care items; (ii) state government-held hospital data, to define outcomes; and (iii) government-held pharmaceutical and aged care claims data, to define covariates. N=1500 randomly selected AuSCR registrants will be sent surveys to obtain patient experience information. In Australia, unique identifiers are unavailable. Therefore, personal-identifiers will be submitted to government data linkage units. Researchers will merge the de-identified datasets for analysis using a project identifier. An economic evaluation will also be undertaken.

ANALYSIS

The index event will be the first stroke recorded in the AuSCR. Multivariable competing risks Poisson regression for multiple events, adjusted by a propensity score, will be used to test for differences in the rates of hospital presentations and medication adherence for different care (policy) types. Our estimated sample size of 25,000 patients will provide 80% estimated power (ɑ>0.05) to detect a 6-8% difference in rates. The incremental costs per Quality-adjusted life years gained of community-based care following the acute event will be estimated from a health sector perspective.

CONCLUSION

Completion of this study will provide a novel and comprehensive evaluation of the effectiveness and cost-effectiveness of Australian primary care policies. Its success will enable us to highlight the value of data-linkage for this type of research.

Early mobilization and quality of life after stroke: Findings from AVERT

OBJECTIVE

To determine whether early and more frequent mobilization after stroke affects health-related quality of life.

METHODS

A Very Early Rehabilitation Trial (AVERT) was an international, multicenter (56 sites), phase 3 randomized controlled trial, spanning 2006-2015. People were included if they were aged ≥18 years, presented within 24 hours of a first or recurrent stroke (ischemic or hemorrhagic), and satisfied preordained physiologic criteria. Participants were randomized to usual care alone or very early and more frequent mobilization in addition to usual care. Quality of life at 12 months was a prespecified secondary outcome, evaluated using the Assessment of Quality of Life 4D (AQoL-4D). This utility-weighted scale has scores ranging from -0.04 (worse than death) to 1 (perfect health). Participants who died were assigned an AQoL-4D score of 0.

RESULTS

No significant difference in quality of life at 12 months between intervention (median 0.47, interquartile range [IQR] 0.07-0.81) and usual care (median 0.49, IQR 0.08-0.81) groups was identified (p = 0.86), nor were there any group differences across the 4 AQoL-4D domains. The same lack of group difference in quality of life was observed at 3 months. When cohort data were analyzed (both groups together), quality of life was strongly associated with acute length of stay, independence in activities of daily living, cognitive function, depressive symptoms, and anxiety symptoms (all p < 0.001). Quality of life in AVERT participants was substantially lower than population norms, and the gap increased with age.

CONCLUSIONS

Earlier and more frequent mobilization after stroke did not influence quality of life.

CLINICAL TRIAL REGISTRATION

anzctr.org.au; ACTRN12606000185561 CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for people with stroke, earlier and more frequent mobilization did not influence quality of life over the subsequent year.

Process evaluation in the field: global learnings from seven implementation research hypertension projects in low-and middle-income countries

BACKGROUND

Process evaluation is increasingly recognized as an important component of effective implementation research and yet, there has been surprisingly little work to understand what constitutes best practice. Researchers use different methodologies describing causal pathways and understanding barriers and facilitators to implementation of interventions in diverse contexts and settings. We report on challenges and lessons learned from undertaking process evaluation of seven hypertension intervention trials funded through the Global Alliance of Chronic Diseases (GACD).

METHODS

Preliminary data collected from the GACD hypertension teams in 2015 were used to inform a template for data collection. Case study themes included: (1) description of the intervention, (2) objectives of the process evaluation, (3) methods including theoretical basis, (4) main findings of the study and the process evaluation, (5) implications for the project, policy and research practice and (6) lessons for future process evaluations. The information was summarized and reported descriptively and narratively and key lessons were identified.

RESULTS

The case studies were from low- and middle-income countries and Indigenous communities in Canada. They were implementation research projects with intervention arm. Six theoretical approaches were used but most comprised of mixed-methods approaches. Each of the process evaluations generated findings on whether interventions were implemented with fidelity, the extent of capacity building, contextual factors and the extent to which relationships between researchers and community impacted on intervention implementation. The most important learning was that although process evaluation is time consuming, it enhances understanding of factors affecting implementation of complex interventions. The research highlighted the need to initiate process evaluations early on in the project, to help guide design of the intervention; and the importance of effective communication between researchers responsible for trial implementation, process evaluation and outcome evaluation.

CONCLUSION

This research demonstrates the important role of process evaluation in understanding implementation process of complex interventions. This can help to highlight a broad range of system requirements such as new policies and capacity building to support implementation. Process evaluation is crucial in understanding contextual factors that may impact intervention implementation which is important in considering whether or not the intervention can be translated to other contexts.

Prevalence of diabetes and pre-diabetes in rural Tehri Garhwal, India: influence of diagnostic method

Background

There are few available data regarding the prevalence of diabetes in the sub-Himalayan region of India. The aim of this study was to determine the prevalence of pre-diabetes and diabetes in rural Garhwal based on glycosylated hemoglobin.

Methods

In a cross-sectional survey of 500 adults from five randomly selected villages in Chamba, a mountainous Tehri Garhwal district in Uttarakhand in north-west India, we determined the prevalence of diabetes (hemoglobin (Hb) A_1c ≥ 6.5%) and pre-diabetes (5.7% ≤ HbA_1c ≤ 6.4%). In a sub-sample of those diagnosed with diabetes or pre-diabetes (n = 140), fasting blood glucose (FBG, n = 117) or postprandial blood glucose (PBG, n = 23), and blood hemoglobin concentration, was measured at follow-up.

Results

Based on HbA_1c, 10.0% had diabetes and 56.4% pre-diabetes. Of those diagnosed as diabetic by HbA_1c, 10 of 16 (62.5%) were diagnosed as diabetic by FBG (> 125 mg/dL) or PBG (≥200 mg/dL). In those diagnosed as pre-diabetic by HbA_1c, only 55 of 124 (44.4%) were diagnosed as pre-diabetic by FBG (100–125 mg/dL) or PBG (140–199 mg/dL). A large proportion of these 140 individuals (67.1%) were moderately to severely anemic (Hb < 11.4 mg/dL). The diagnostic gap for pre-diabetes between HbA_1c and FBG/PBG was similar for the groups with and without moderate to severe anemia.

Conclusions

HbA_1c and FBG/PBG have similar diagnostic performance for diabetes in this population. However, many individuals were diagnosed with pre-diabetes by HbA_1c but not FBG/PBG. The relative excess diagnosis of pre-diabetes with HbA_1c does not appear to be explained by anemia, an endemic condition in India. The prognostic significance of diagnosis of pre-diabetes by HbA_1c but not FBG/PBG remains unknown, but merits investigation.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7184-4) contains supplementary material, which is available to authorized users.

Multicenter, Prospective, Controlled, Before-and-After, Quality Improvement Study (Stroke123) of Acute Stroke Care

Supplemental Digital Content is available in the text.

Background and Purpose—

Hospital uptake of evidence-based stroke care is variable. We aimed to determine the impact of a multicomponent program involving financial incentives and quality improvement interventions, on stroke care processes.

Methods—

A prospective study of interventions to improve clinical care quality indicators at 19 hospitals in Queensland, Australia, during 2010 to 2015, compared with historical controls and 23 other Australian hospitals. After baseline routine audit and feedback (control phase, 30 months), interventions involving financial incentives (21 months) and then addition of externally facilitated quality improvement workshops with action plan development (9 months) were implemented. Postintervention phase was 13 months. Data were obtained for the analysis from a previous continuous audit in Queensland and subsequently the Australian Stroke Clinical Registry. Primary outcome: change in median composite score for adherence to ≤8 indicators. Secondary outcomes: change in adherence to self-selected indicators addressed in action plans and 4 national indicators compared with other Australian hospitals. Multivariable analyses with adjustment for clustered data.

Results—

There were 17 502 patients from the intervention sites (median age, 74 years; 46% women) and 20 484 patients from other Australian hospitals. Patient characteristics were similar between groups. There was an 18% improvement in the primary outcome across the study periods (95% CI, 12%–24%). The largest improvement was following introduction of financial incentives (14%; 95% CI, 8%–20%), while indicators addressed in action plans provided an 8% improvement (95% CI, 1%–17%). The national score (4 indicators) improved by 17% (95% CI, 13%–20%) versus 0% change in other Australian hospitals (95% CI, −0.03 to 0.03). Access to stroke units improved more in Queensland than in other Australian hospitals (P<0.001).

Conclusions—

The quality improvement interventions significantly improved clinical practice. The findings were primarily driven by financial incentives, but were also contributed to by the externally facilitated, quality improvement workshops. Assessment in other regions is warranted.

Global, regional, and national burden of stroke, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Stroke is a leading cause of mortality and disability worldwide and the economic costs of treatment and post-stroke care are substantial. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic, comparable method of quantifying health loss by disease, age, sex, year, and location to provide information to health systems and policy makers on more than 300 causes of disease and injury, including stroke. The results presented here are the estimates of burden due to overall stroke and ischaemic and haemorrhagic stroke from GBD 2016.

METHODS

We report estimates and corresponding uncertainty intervals (UIs), from 1990 to 2016, for incidence, prevalence, deaths, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs). DALYs were generated by summing YLLs and YLDs. Cause-specific mortality was estimated using an ensemble modelling process with vital registration and verbal autopsy data as inputs. Non-fatal estimates were generated using Bayesian meta-regression incorporating data from registries, scientific literature, administrative records, and surveys. The Socio-demographic Index (SDI), a summary indicator generated using educational attainment, lagged distributed income, and total fertility rate, was used to group countries into quintiles.

FINDINGS

In 2016, there were 5·5 million (95% UI 5·3 to 5·7) deaths and 116·4 million (111·4 to 121·4) DALYs due to stroke. The global age-standardised mortality rate decreased by 36·2% (-39·3 to -33·6) from 1990 to 2016, with decreases in all SDI quintiles. Over the same period, the global age-standardised DALY rate declined by 34·2% (-37·2 to -31·5), also with decreases in all SDI quintiles. There were 13·7 million (12·7 to 14·7) new stroke cases in 2016. Global age-standardised incidence declined by 8·1% (-10·7 to -5·5) from 1990 to 2016 and decreased in all SDI quintiles except the middle SDI group. There were 80·1 million (74·1 to 86·3) prevalent cases of stroke globally in 2016; 41·1 million (38·0 to 44·3) in women and 39·0 million (36·1 to 42·1) in men.

INTERPRETATION

Although age-standardised mortality rates have decreased sharply from 1990 to 2016, the decrease in age-standardised incidence has been less steep, indicating that the burden of stroke is likely to remain high. Planned updates to future GBD iterations include generating separate estimates for subarachnoid haemorrhage and intracerebral haemorrhage, generating estimates of transient ischaemic attack, and including atrial fibrillation as a risk factor.

FUNDING

Bill & Melinda Gates Foundation.

Evaluating recruitment strategies for AUSPICE, a large Australian community-based randomised controlled trial

OBJECTIVES

To examine the effectiveness of different strategies for recruiting participants for a large Australian randomised controlled trial (RCT), the Australian Study for the Prevention through Immunisation of Cardiovascular Events (AUSPICE).

DESIGN, SETTING, PARTICIPANTS

Men and women aged 55-60 years with at least two cardiovascular risk factors (hypertension, hypercholesterolaemia, overweight/obesity) were recruited for a multicentre placebo-controlled RCT assessing the effectiveness of 23-valent pneumococcal polysaccharide vaccine (23vPPV) for preventing cardiovascular events.

METHODS

Invitations were mailed by the Australian Department of Human Services to people in the Medicare database aged 55-60 years; reminders were sent 2 weeks later. Invitees could respond in hard copy or electronically. Direct recruitment was supplemented by asking invitees to extend the invitation to friends and family (snowball sampling) and by Facebook advertising.

MAIN OUTCOME

Proportions of invitees completing screening questionnaire and recruited for participation in the RCT.

RESULTS

21 526 of 154 992 invited people (14%) responded by completing the screening questionnaire, of whom 4725 people were eligible and recruited for the study. Despite the minimal study burden (one questionnaire, one clinic visit), the overall participation rate was 3%, or an estimated 10% of eligible persons. Only 16% of eventual participants had responded within 2 weeks of the initial invitation letter (early responders); early and late responders did not differ in their demographic or medical characteristics. Socio-economic disadvantage did not markedly influence response rates. Facebook advertising and snowball sampling did not increase recruitment.

CONCLUSIONS

Trial participation rates are low, and multiple concurrent methods are needed to maximise recruitment. Social media strategies may not be successful in older age groups.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12615000536561.

Sex Differences in Care and Long-Term Mortality After Stroke: Australian Stroke Clinical Registry

Introduction: There is some evidence that women receive evidence-based care less often than men, but how this influences long-term mortality after stroke is unclear. We explored this issue using data from a national stroke registry. Materials and Methods: Data are first-ever hospitalized strokes (2010-2014) in the Australian Stroke Clinical Registry from 39 hospitals linked to the national death registrations. Multilevel Poisson regression was used to estimate the women:men mortality rate ratio (MRR), with adjustment for sociodemographics, stroke severity, and processes of care (stroke unit care, intravenous thrombolysis, antihypertensive agent[s], and discharge care plan). Results: Among 14,118 events (46% females), women were 7 years older and had greater baseline severity compared to men (29% vs. 37%; p < 0.001), but there were no differences in the four processes of care available across hospitals. In the whole cohort, 1-year mortality was greater in women than men (MRR_unadjusted 1.44, 95% confidence interval [CI] 1.34-1.54). However, there were no differences after adjusting for age and stroke severity (MRR_adjusted 1.03, 95% CI 0.95-1.10). In analyses of additional processes from Queensland hospitals (n = 5224), women were less often administered aspirin ≤48 hours (61% vs. men 69%, p < 0.015). In Queensland hospitals, there were no statistically significant sex differences in 1-year mortality after adjusting for age, stroke severity, and early administration of aspirin. Conclusion: Greater mortality in women can be explained by differences in age and stroke severity. This highlights the importance of better management of risk factors in the elderly and, potentially, the need for greater access to early aspirin for women with stroke.

Knowledge of risk factors for hypertension in a rural Indian population

Objective

To study knowledge of risk factors and consequences of hypertension in a rural population in South India.

Methods

This is a community-based study conducted among adults of a rural population in the Rishi Valley, India. Residents of randomised rural villages were invited to participate in a study of hypertension. We obtained measures of blood pressure, height, weight, waist and hip circumferences and questionnaire-based information on knowledge about hypertension, sociodemographic characteristics and health behaviours. Multivariable logistic regression analyses were conducted to determine the factors associated with knowledge of risk factors for hypertension (knowledge of ≥2 risk factors).

Results

The study comprised 641 adults; 132 aware and 218 unaware of their hypertension, and 291 with normal blood pressure. Only 31% of participants knew that hypertension adversely affects an individual's health and 7% knew the benefits of treating hypertension. Almost a third (30%) of those aware of their hypertensive status, and 48% overall, did not know any of the risk factors for hypertension. Being aware of one's hypertensive status (OR 2.51, 95% CI 1.44 to 4.39), being treated for hypertension, male sex, younger age, having some schooling, abdominal obesity and physical inactivity were associated with better knowledge of risk factors for hypertension.

Conclusion

Knowledge of risk factors and consequences of hypertension in this disadvantaged population was poor. There was better knowledge of risk factors in some, but not all, people who were aware of having hypertension. Screening and targeted educational programmes are warranted in this population to improve health behaviours and reduce the consequences of hypertension.

Age, sex, and setting in the etiology of stroke study (ASSESS): Study design and protocol

RATIONALE

Stroke etiology and risk factors vary by age, sex, setting (hospital or community-based) and by region. Identifying these differences would improve our understanding of stroke etiology, diagnosis, and treatment.

AIM

The Age, Sex and Setting in the Etiology of Stroke Study (ASSESS) is a multicenter cohort study to assess differences in stroke etiology.

METHODS AND DESIGN

Data from all centers will be categorized according to age, sex, setting, stroke subtypes. Centers with extensive hospital- or community-based data regarding stroke from Argentina, Australia, Canada, India, Iran, Italy, Ghana, Nigeria, Thailand, the United Kingdom and the United States have agreed to participate so far.

STUDY OUTCOMES

The primary outcome includes differences in stroke etiology in study centers. The secondary outcomes include stroke incidence, risk factors, preventive strategies, and short- and long-term outcomes.

CONCLUSION

ASSESS will enable comparisons of data from different regions to determine the age and sex distribution of the most common causes of stroke in each setting. This will help clinicians to tailor the assessment and treatment of stroke patients on the basis of their specific local characteristics. It will also empower stroke epidemiologists to design preventive measures by targeting the specific characteristics of each population.

Abstract WP237: Risk Factors for Aneurysmal Subarachnoid Hemorrhage in Women: Systematic Review and Meta-Analysis

Background: Aneurysmal subarachnoid hemorrhage (aSAH) affects women more than men, unlike other stroke types. We completed a systematic review and meta-analysis of risk factors associated with the occurrence of aSAH in women.

Methods: A systematic search was conducted using the Pubmed, Scopus, Embase, and Medline databases from inception to November 2017 to identify studies that included aSAH risk factors among women only or mentioned female sex as a risk factor. The risk factors were assessed using meta-analysis if reported by at least two studies.

Results: Fourteen studies (10 case-control; 4 cohort) were included. Female sex was associated with higher odds or risk of aSAH in pooled estimates of cohort studies (HR adjusted 1.90, 95% CI 1.47-2.46) but not in case-control studies (OR adjusted 1.44, 95% CI 0.83-2.52). Menarche at an early age (age <12 years HR crude 1.15 [95% CI 0.52-2.55], age <13 years OR adjusted 3.24 [95% CI 1.25-4.03]), pregnancy at ≥26 years (OR adjusted 1.78 [95% CI 1.13-2.80]), use of contraceptive pills (RR crude range, 5.3-6.5), nulligravidity (OR adjusted 4.23 [95% CI 1.05-7.56]), aSAH predilection area (RR crude 1.81) and being divorced (RR crude 1.89) increased the risk for aSAH in women. Parity moderately decreased the risk for aSAH (parity >3 HR crude 1.21 [95% CI 0.68-2.14], parity=2 OR adjusted 0.87 [95% CI 0.64-1.19], parity ≥5, OR adjusted 0.25 [95% CI 0.03-1.89]).

Conclusion: A number of risk factors, primarily related to reproductive hormones, for aSAH were identified in women. These could be potential causes of higher incidence of aSAH in women compared to men. There is a need for further research focused on aSAH in order to explore the association of these risk factors with aSAH in women.

Abstract WMP58: Sex Differences in Risk Factors for Aneurysmal Subarachnoid Hemorrhage: Systematic Review and Meta-Analysis

Background: Aneurysmal subarachnoid hemorrhage (aSAH) disproportionally affects women. The etiology of this is unclear, and the contribution of sex differences in aSAH risk factors is unknown. We aimed to identify sex differences in aSAH risk factors in a systematic review and meta-analysis.

Methods: A systematic search was conducted using the Pubmed, Scopus, Embase, and Medline databases from inception to November 2017 to identify studies that included aSAH risk factors stratified by sex. aSAH risk factors were assessed using meta-analysis with pooled odds ratios (OR) calculated for risk factors with at least 2 studies.

Results: There were 34 eligible case-control studies; however, 15 did not report sex specific findings with 19 were included. Hypertension (men pooled OR adjusted 3.13 [95% CI 2.26-4.34]; women pooled OR adjusted 3.65 [95% CI 2.87-4.63], p=0.18), smoking (men pooled OR adjusted 2.96 [95% CI 1.68-5.21]; women pooled OR adjusted 3.11 [95% CI 1.21-7.97], p=0.95), family history of aSAH, increased systolic blood pressure, age, angiotensin-converting enzyme gene polymorphism and variation in a protease gene had the same odds for aSAH in both sexes. Alcohol intake (men pooled OR adjusted 1.50 [95% CI 1.04-2.17], women pooled OR adjusted 0.83 [95% CI 0.48-1.45], p=0.003), high alanine aminotransferase levels, and endothelial nitric oxide synthase gene variant were associated with higher odds of aSAH in men than women. Cold temperature, polymorphisms in factor XIII gene and genetic variation on chromosome 9p21 increased the odds of aSAH in women but not men. High aspartate aminotransferase levels were associated with a reduced risk in men while diabetes mellitus decreased the risk in women (men pooled OR adjusted 0.57 [95% CI 0.32-1.01], women pooled OR adjusted 0.24 [95% CI 0.13-0.43], p=0.017).

Conclusion: Except for alcohol intake and diabetes mellitus, the magnitude of aSAH risk associated with most common risk factors were similar for both sexes. We advocate for re-analysis of existing studies with regard to sex differences.

Abstract TP396: Accuracy of Administrative Hospital, Emergency Department and Death Records

Background: Hospital, emergency presentation and death databases are frequently used to research outcomes after stroke. The reliability of diagnostic coding for cardiovascular disease (CVD) in these administrative data remains uncertain. We aimed to determine the reliability of these data in Australia using an existing clinical trial cohort.

Methods: Patients with stroke/TIA who participated in the Shared Team Approach between Nurses and Doctors For Improved Risk factor Management (STAND FIRM) trial (n = 563, recruited from 4 hospitals within Victoria). We used diagnostic ICD-10-AM coded data from hospital, emergency department and death databases within 2 years after stroke/TIA. Medical records for these potential CVD-related events were reviewed by two independent stroke specialists and adjudicated according to strict criteria. We then estimated sensitivity and specificity of using either primary or both primary and secondary diagnoses fields (obtained for all adjudicated records), against the events adjudicated by the specialists (gold standard). False positives were CVD-events defined by ICD-10-AM diagnostic codes that were adjudicated as not being a CVD-event. False negatives were true CVD-events that were misclassified as not being CVD-related when using ICD-10-AM codes.

Results: We identified 261 events for medical review. After adjudication, 65 were classified as CVD-events (cases) and 196 were not CVD-events. Using both primary and secondary diagnoses, 55 true positives were correctly identified among the cases (sensitivity = 84.6%) and 129 true negatives among the non-cases (specificity = 65.8%). Using only primary diagnoses, 48 true positives were identified (sensitivity = 73.9%) and 171 true negatives (specificity = 87.2%). Using both primary and secondary diagnoses had an increased sensitivity, but decreased specificity (area under the Receiver Operating Characteristic curve (AUC) = 0.75; 95% CI, 0.70, 0.81) when compared with using only primary diagnoses (AUC = 0.81; 95% CI, 0.75, 0.86; p = 0.028).

Conclusion: Both primary and secondary diagnoses should be used to identify true CVD-events and minimise misclassifying these in administrative databases.